A Guide to the Engine Crankshaft Position Sensor for the 2016-2020 Kia Optima
Understanding the symptoms and choosing the right replacement sensor to prevent stalling and starting issues in your Optima.
- A failing crankshaft sensor is a primary cause of stalling, no-start issues, and a P0335 code.
- Driving with a bad sensor is unsafe due to the risk of the engine shutting off while in motion.
- For best results, choose an OE-equivalent brand like Mando, Delphi, or Hitachi over budget brands.
- Replacement is a feasible DIY task for those with basic tools, potentially saving over $100 in labor.
Is Your Kia Optima Stalling or Not Starting? It Could Be the Crankshaft Sensor.
If your 2016-2020 Kia Optima is experiencing sudden engine stalls, having trouble starting, or the check engine light is on, a faulty engine crankshaft position sensor is a common culprit. This small electronic part plays a huge role in your engine's operation, and when it fails, it can cause serious and potentially dangerous problems. This guide will help you understand the symptoms, what to look for in a replacement, and what to expect for repair costs.
Common Symptoms of a Bad Crankshaft Position Sensor
A failing crankshaft sensor will usually give you clear warning signs. The most common issue is the illumination of the Check Engine Light, often with the diagnostic trouble code (DTC) P0335. Other signs include:
- Engine Stalling: The engine may shut off unexpectedly while you are driving, which is a critical safety issue.
- No-Start or Hard Start: Your Optima may crank but refuse to start, or take much longer than usual to fire up. This can sometimes get worse as the engine gets hot.
- Rough Idle and Misfires: The engine may shake, vibrate, or run unevenly at idle due to incorrect ignition timing.
- Poor Acceleration: You may notice the car feels sluggish or hesitant when you press the gas pedal.
- Reduced Fuel Economy: When the engine timing is off, it burns fuel less efficiently, hurting your gas mileage.
Important Note on Recalls
While there are no specific recalls for the crankshaft position sensor itself on the 2016-2020 Optima, Kia has issued major engine-related recalls for issues that also cause stalling. It is wise to check with a Kia dealer to see if any open recalls apply to your vehicle's VIN. Replacing a faulty sensor is a good first step in diagnosing a stalling problem.
Choosing the Right Aftermarket Sensor
When it comes to critical electronic sensors, quality matters. A cheap, unreliable sensor can fail quickly, leaving you with the same problem. Not all aftermarket brands are created equal. Here is a breakdown of available brands to help you choose.
Pro Tip: Mando is a known original equipment (OE) manufacturer for Hyundai and Kia. Choosing a Mando-branded sensor is often the same as getting the genuine part without the dealership packaging and price.
Tier 1: OE-Equivalent Quality
- Mando: Often the original part manufacturer for Kia. The safest bet for a perfect fit and long-term reliability.
- Delphi: A major OE supplier for many carmakers, known for high-quality electronics that meet or exceed factory standards.
- Hitachi: Another top-tier OE manufacturer with a strong reputation for reliable sensors.
Tier 2: Reliable Aftermarket
- NGK/NTK: A highly respected brand, famous for spark plugs and other ignition sensors. A solid choice.
- Standard Ignition (SMP): A long-standing company in the aftermarket with a reputation for quality replacement parts.
- Beck Arnley: This brand sources parts from various manufacturers, often including OE suppliers, and is generally considered a quality option.
Tier 3: Budget Options
- Dorman: Dorman has a very mixed reputation for electronic parts. While some products are fine, many professional mechanics report high failure rates for their sensors. It may work, but it's a gamble compared to the brands above.
- Walker Products, Global Parts, Holstein: These brands typically fall into the standard or economy category. They can be a cost-effective solution, but may not have the same longevity or rigorous testing as OE-level brands.
Cost to Replace the Crankshaft Sensor
The cost can be broken down into the part itself and the labor to install it. Since the job is fairly accessible, labor costs are not excessive.
| Item | Estimated Cost |
|---|---|
| New OEM Part | $90 - $130 |
| New Aftermarket Part | $25 - $154 |
| Shop Labor | $100 - $150 |
| Total (Aftermarket Part + Labor) | $125 - $304 |
Frequently Asked Questions
Where is the crankshaft sensor located on a 2016-2020 Kia Optima?
For the common 2.4L engine, the sensor is on the rear of the engine block, near the area where the engine connects to the transmission. It is typically held in by a single 10mm bolt and may be covered by a small metal heat shield.
Can I drive my Optima with a bad crankshaft sensor?
It is not recommended. The most dangerous symptom is the engine stalling while driving, which can lead to a loss of power steering and brakes, increasing the risk of a crash. If the car won't start, you'll be stranded. It's best to get the vehicle repaired as soon as possible.
Is this a difficult DIY repair?
For someone with basic mechanical skills and tools, it is a manageable job. The main challenge is accessing the sensor, which is in a tight spot. The process involves disconnecting the electrical connector, removing one or two small bolts for the heat shield, and one bolt for the sensor itself. Estimated time is 1-1.5 hours for a first-timer.
🎬 Watch: Step-by-step replacement guide for the crankshaft position sensorDo I need to perform an ECU reset after replacing the sensor?
After replacing the sensor, the Check Engine Light code (like P0335) needs to be cleared from the ECU. This can be done with an OBD-II scanner. In most cases, you do not need a special 'relearn' procedure for this specific part; simply clearing the code is sufficient.
🎬 See this walkthrough on testing and fixing the P0335 circuitHelpful Videos
Technical Specifications
OEM Part Numbers: 39180-2G000 39180-2E600 39180-25300 39180-2B030
The sensor is typically a 3-pin Hall effect sensor that reads the rotation of the crankshaft. It is mounted on the engine block and secured with a single bolt.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Kia Optima:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is Your Kia Optima Stalling or Not Starting? It Could Be the Crankshaft Sensor.
- Common Symptoms of a Bad Crankshaft Position Sensor
- Important Note on Recalls
- Choosing the Right Aftermarket Sensor
- Tier 1: OE-Equivalent Quality
- Tier 2: Reliable Aftermarket
- Tier 3: Budget Options
- Cost to Replace the Crankshaft Sensor
- Frequently Asked Questions
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